The human ATG4D

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

encodes the

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

Autophagy related 4D, cysteine peptidase.

Function

Autophagy is the process by which endogenous proteins and damaged

organelles In cell biology, an organelle is a specialized subunit, usually within a cell, that has a specific function. The name ''organelle'' comes from the idea that these structures are parts of cells, as organs are to the body, hence ''organelle,'' th ...

are destroyed intracellularly. Autophagy is postulated to be essential for cell

homeostasis In biology, homeostasis (British English, British also homoeostasis) Help:IPA/English, (/hɒmɪə(ʊ)ˈsteɪsɪs/) is the state of steady internal, physics, physical, and chemistry, chemical conditions maintained by organism, living systems. Thi ...

and cell remodeling during differentiation, metamorphosis, non-

apoptotic Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes ( morphology) and death. These changes inc ...

cell death, and aging. Reduced levels of autophagy have been described in some malignant

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

s, and a role for autophagy in controlling the unregulated cell growth linked to

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...

has been proposed. This gene belongs to the autophagy-related protein 4 (Atg4) family of C54

endopeptidases Endopeptidase or endoproteinase are proteolytic peptidases that break peptide bonds of nonterminal amino acids (i.e. within the molecule), in contrast to exopeptidases, which break peptide bonds from end-pieces of terminal amino acids. For this re ...

. Members of this family encode proteins that play a role in the biogenesis of autophagosomes, which sequester the

cytosol The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells ( intracellular fluid (ICF)). It is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondri ...

and organelles for degradation by

lysosome A lysosome () is a membrane-bound organelle found in many animal cells. They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules. A lysosome has a specific composition, of both its membrane ...

s. Alternative splicing results in multiple

transcript Transcript may refer to: * Transcript (biology), a molecule of RNA transcribed from DNA * Transcript (education), a copy of a student's permanent academic record * Transcript (law), a written record of spoken language in court proceedings * Tr ...

variants. rovided by RefSeq, Jul 2013

Function

References

Further reading